On a Friday afternoon before a long holiday weekend, a company’s security operations center receives a potentially serious alert: It appears that a domain controller has been tampered with. After examining event logs and overlaying network traffic, a SOC analyst confirms that a suspicious system did in fact connect to the controller, extracted credentials, and performed other actions.

Worried this could be a hacker, the SOC team spends hours doing network analysis. Eventually they determine it’s a false alarm: An administrator had logged into the network to check his email with his personal laptop, whose use the company had authorized a month before.

Why did it take the SOC team so long to solve this mystery? They lacked a comprehensive IT asset inventory that would have allowed them to either quickly find that laptop on a list of devices owned by employees and approved for work use, or else determine it was a rogue device.

This hypothetical incident shows the importance of a continuously updated IT asset inventory, which would have slashed the SOC’s investigation time, and made a big difference if instead there had been an attack, according to security experts from SANS Institute and from Qualys.

Black Hat attendees got a peek at Qualys Passive Network Sensor (PNS), a product that amplifies the already comprehensive IT asset visibility Qualys provides to its customers. By adding real-time network analysis to Qualys’ versatile set of sensors, PNS eliminates blind spots across IT environments through continuous traffic monitoring.

“Now you have instant visibility into every single asset that’s communicating on your network,” said Qualys’ Chief Product Officer Sumedh Thakar during a presentation on Passive Network Sensor at the conference.

The sensor extends the Qualys Cloud Platform’s broad spectrum of integrated security and compliance capabilities, further reducing Qualys customers’ needs for multi-vendor point products that are costly to manage and integrate.